Rebels battle into the night to control military base just outside Damascus

Rebels battle into the night to control a helicopter base just outside Damascus.
They say they destroyed two helicopters and took 15 people captive.
It is their latest gain in a costly battle to unseat President Bashar al-Assad.
The video, which could not be independently verified by Reuters, comes as rebel forces draw nearer to Assad's seat of power.
A Western diplomat told Reuters that Assad still had the upper hand in the fight.
It's a fight that activists say has already cost the lives of 40,000 people.